1. Field of the Invention
The present invention relates to a recording tape cartridge. In particular, the cartridge rotatably accommodates a single reel on which a recording tape, such as a magnetic tape or the like, is wound. During use, the recording tape is taken-up onto a take-up reel of a drive device.
2. Description of the Related Art
Recording tapes such as magnetic tapes and the like are used as external storage media for computers and the like. There are recording tapes on which a large amount of information can be recorded although the space for accommodating the recording tape during storage thereof is small. A recording tape cartridge, which accommodates, in a case, a single reel on which the recording tape is wound, is used for the recording tape.
When such a recording tape cartridge is used, i.e., when information is to be recorded onto the recording tape or information recorded on the recording tape is to be played back therefrom, the recording tape cartridge is loaded into a drive device. At the drive device in which the recording tape cartridge is loaded, a leader member, which is attached to the distal end of the recording tape, is pulled-out from the case by a pull-out means.
The leader member is guided to a take-up reel of the drive device by the pull-out means. The recording tape is pulled-out successively from the case while being taken-up on to the take-up reel, and recording or playing back of information is carried out by a recording/playback head or the like disposed along a predetermined tape path.
A leader block, which is formed in a block-shape, is an example of the above-described leader member. Further, a leader pin, which is shaped as a small, solid cylinder, and a leader tape, which is formed in a thick tape-shape which is thicker than the recording tape, are also known as other leader members.
In a recording tape cartridge having a leader block, when the recording tape is taken-up onto the take-up reel, the leader block is accommodated within a reel hub of the take-up reel. A curved end surface of the leader block, together with the outer peripheral surface of the reel hub, forms the take-up surface for the recording tape.
However, the leader block is a member of the recording tape cartridge. At each recording tape cartridge which is loaded into the drive device, there are individual differences in the accuracy of the dimensions of the leader block. Thus, the degree of smoothness of the take-up surface on which the recording tape is taken-up depends on the dimensional accuracy of each leader block. The drive device cannot absorb these individual differences in the dimensional accuracies of leader blocks. Thus, there are cases in which a step, which is unacceptable, arises between the end surface of the leader block and the take-up surface of the reel hub, i.e., the edge portion of the opening of the leader block accommodating portion of the reel hub.
Such a step causes a step (a fold or deformation) in the recording tape which is taken up. This step similarly arises at the portion of the recording tape which is wound up as the next layer or subsequent layers and which is substantially a recording region. At the portion of the recording tape where such a step arises, in the process of recording or playing back information, an appropriate distance with the recording/playback head cannot be maintained. Accordingly, such a deformed portion results in the formation of regions at which information cannot be recorded, or results in the loss of recorded information.
In particular, the opening width of the accommodating portion of the reel hub which accommodates the block-shaped leader block is large. For example, in the case of a 12.7 mm wide recording tape, the opening width at the outer peripheral portion of a reel hub having a diameter of 50 mm is about 12 mm. Accordingly, the effects caused by individual differences in the dimensions of leader blocks is great, and the probability that the above-described problems will occur is high.
Moreover, in a recording tape cartridge having a leader pin, when the recording tape is taken-up onto the take-up reel, the leader pin is, together with a leader block forming the pull-out means of the drive device, accommodated within the reel hub of the take-up reel. The curved end surface of the leader block of the drive device, together with the outer peripheral surface of the reel hub, forms the take-up surface for the recording tape. This leader block is structured to move from a position at which the leader block catches the leader pin which is accommodated within the case (the recording tape cartridge), to a position of being accommodated within the reel hub, by, for example, a cam mechanism or an arm mechanism having a pin which engages with a pass-through hole of the leader block.
In this structure, the leader block, which is a member of the drive device, forms a portion of the take-up surface. Thus, in other words, the leader block, together with the reel hub, form portions of the drive device, and are provided in a one-to-one correspondence. Accordingly, the step at the take-up surface is not affected by the individual differences in dimensional accuracies of leader pins, which are parts of recording tape cartridges.
However, the leader block which forms the pull-out means can move within the reel hub in order to cancel engagement of the pin and the pass-through hole in the state in which the leader block is accommodated in the reel hub, in order for the cam mechanism and the like to not impede rotation of the reel hub. This is not a structure in which positioning is carried out by the leader block abutting the reel hub. Thus, there are cases in which accurate positioning within the reel hub cannot be carried out due to the accumulation of operational errors of a plurality of cam mechanisms or arm mechanisms caused by a complex path corresponding to the predetermined tape path being moved by the plurality of cam mechanisms or arm mechanisms.
Namely, in this structure, there are cases in which a step arises due to the deformed portion of the tape between the leader block end surface and the take-up surface, i.e., the edge portion of the opening of the leader block (leader pin) accommodating portion of the reel hub, due to the positioning accuracy of the leader block of the drive device with respect to the reel hub.
Moreover, in a recording tape cartridge having a leader tape, in a state in which one end portion of a tape-shaped take-up leader, whose other end portion is fixed to the reel hub of the take-up reel, has entered into an engagement hole of the leader tape and has caught on the leader tape, the recording tape is taken-up onto the reel hub together with the leader tape and the take-up leader. In this structure, the recording tape is taken-up on the take-up leader and the leader tape which are taken-up on the reel hub. Accordingly, there are hardly any cases in which a step of the leader hub itself becomes a problem.
However, the one end portion of the take-up leader enters in (passes through) the engagement hole of the leader tape. In other words, taking-up onto the reel hub is carried out in a state which is as if respective end portions of the leader tape and the take-up leader, which are both thicker than the recording tape, are superposed together. Thus, a step which is a cause of deformation of a tape arises at this superposed portion. Accordingly, in a structure having a leader tape, there has been the need for a special countermeasure, such as making the leader tape long and winding it several times at the step portion, in order to prevent the deformation.
In view of the aforementioned, an object of the present invention is to provide a recording tape cartridge which can make small the step which arises at a recording tape at the time when the recording tape is taken-up onto a reel hub of a drive device.
In order to achieve the above-described object, a recording tape cartridge relating to the present invention comprises: a recording tape which is wound on a single reel rotatably accommodated in a case, and at which one of recording of information and playback of information is carried out while the recording tape is being taken-up onto a reel hub of a drive device; a leader member formed in a thin-plate shape and connected to a distal end of the recording tape, and when the recording tape is taken-up onto the reel hub, the leader member is accommodated along an entire length of the leader member in a slit which opens at an outer peripheral surface of the reel hub; and an engaging portion provided at a transverse direction end portion of the leader member, and positioned at an outer side of the slit at a time when the leader member is accommodated in the slit.
When the recording tape cartridge of the present invention is loaded into a drive device at the time when the recording tape cartridge is to be used, the leader member, which is connected to the distal end of the recording tape, is pulled-out from the case together with the engaging portion. The leader member is accommodated (inserted), along the entire length thereof, into a slit of a reel hub which forms the drive device.
In this state, the engaging portion, which is provided at the transverse direction end portion of the leader member, is positioned at the outer side of the slit (e.g., at the outer side in the axial direction of the reel hub). The engaging portion has at least one of the following functions: a function of positioning the leader member within the case, a function of being anchored (held) at the reel hub, and a function of being manipulated (guided to the reel hub while being grasped or caught or the like) by the pull-out means of the drive device. Or, a member having at least some of the above-described functions is attached to the engaging portion.
In this way, the thin-plate-shaped leader member, including the region thereof connected with the recording tape, is accommodated in the slit without projecting out from the opening portion of the slit at the outer peripheral surface of the reel hub. When the reel hub is driven to rotate in this state, the recording tape is successively pulled-out from the case while being taken-up onto the outer peripheral surface of the reel hub, and information is recorded or played back by a recording/playback head or the like disposed along a predetermined tape path.
Here, because the leader member is thin-plate-shaped, the slit in which the leader member is accommodated can be made to be thin. There is no need for the slit to accommodate the engaging portion which is provided at the transverse direction end portion of the leader member. In other words, the rectilinear portion which connects the circumferential direction both edge portions of the opening portion of the slit at the outer peripheral surface of the reel hub can be made to be short. Thus, at this opening portion of the slit as well, the recording tape is taken-up (trained) substantially along the circumference prescribing the outer periphery of the reel hub, and no step which would cause deformation is formed at the recording tape.
The entire length of the leader member is inserted into the slit. In other words, at (the longitudinal direction or thickness direction end surface of) the leader member, the recording tape is not trained at the outer side of the reel hub. Thus, no step arises at the take-up surface due to differences in dimensions of individual leader members or due to the positional accuracy within the slit. The thickness of the leader member does not cause a step at the take-up surface.
In this way, in the recording tape cartridge of the present invention, when a recording tape is taken-up onto a reel hub of a drive device, a step which may be formed at the recording tape can be made to be small.